Contemporary data centers are increasingly co-located with power generation or cooling resources to reduce operational costs. Power generation microgrids can take advantage of a variety of local power generation options to reduce the dependence on the utility grid for power.

Microgrids can employ solar cells, wind turbines, biofuels or other sources, many of which are renewable, to generate electricity used to power data centers. The prevalence of dairy farms in the United States presents a co-location opportunity that generates biofuel from farm waste.

HP Labs is committed to designing data centers that are substantially more efficient and use local, renewable energy resources. New research from HP Labs shows how the manure output of cows and the heat output of data centers can be combined to create an economically and environmentally sustainable operation.

In a research paper presented at the ASME International Conference on Energy Sustainability in Phoenix, Ariz., the HP researchers explain how a farm of 10,000 dairy cows could fulfill the power requirements of a 1-megawatt (MW) data center – the equivalent of a medium-sized data center – with power left over to support other needs on the farm.

In this process, the heat generated by the data center can be used to increase the efficiency of the anaerobic digestion of animal waste. This results in the production of methane, which can be used to generate power for the data center. This symbiotic relationship allows the waste problems faced by dairy farms and the energy demands of the modern data center to be addressed in a sustainable manner.

Dairy farms and data centers may appear to be unexpected partners; however, HP Labs has shown that the specific needs and challenges of both can be aligned to create a sustainable life cycle, using technologies readily available today.

* The average dairy cow produces about 55 kg (120 pounds) of manure per day, and approximately 20 metric tons per year – roughly equivalent to the weight of four adult elephants.
* The manure that one dairy cow produces in a day can generate 3.0 kilowatt-hours (kWh) of electrical energy, which is enough to power television usage in three U.S. households per day.(1)
* A medium-sized dairy farm with 10,000 cows produces about 200,000 metric tons of manure per year. Approximately 70 percent of the energy in the methane generated via anaerobic digestion could be used for data center power and cooling, thus reducing the impact on natural resources.
* Pollutants from unmanaged livestock waste degrade the environment and can lead to groundwater contamination and air pollution. Methane is 21 times more damaging to the environment than carbon dioxide, which means that in addition to being an inefficient use of energy, disposal of manure through flaring can result in steep greenhouse gas emission taxes.
* In addition to benefiting the environment, using manure to generate power for data centers could provide financial benefit to farmers. HP researchers estimate that dairy farmers would break even in costs within the first two years of using a system like this and then earn roughly $2 million annually in revenue from selling waste-derived power to data center customers.

“The idea of using animal waste to generate energy has been around for centuries, with manure being used every day in remote villages to generate heat for cooking. The new idea that we are presenting in this research is to create a symbiotic relationship between farms and the IT ecosystem that can benefit the farm, the data center and the environment.” commented Tom Christian, principal research scientist, Sustainable IT Ecosystem Lab.